1. Field of the Invention
The present invention relates to a plasma display device including a plasma display panel (PDP), and a driving method for the PDP.
2. Description of the Related Art
A plasma display device is a flat panel display that uses plasma generated by a gas discharge process to display characters or images. It includes, depending on its size, more than several hundreds of thousands to millions of pixels arranged in a matrix pattern.
Generally, a driving method of the plasma display device may be expressed as operational changes according to time, which include a reset period, an address period, and a sustain period.
The reset period is for initializing the status of each discharge cell to facilitate an addressing operation on the discharge cell. The address period is for selecting turn-on/turn-off cells (i.e., discharge cells to be turned on or off) and accumulating wall charges in the turn-on cells (i.e., addressed discharge cells). The sustain period is for causing a discharge for displaying an image on the addressed cells.
In a driver of the plasma display device, displacement currents corresponding to a reactive power flow to respective discharge cells when sustain pulses are applied, and a sustain discharge is performed because discharge currents flow to the respective discharge cells when a sum of a wall voltage and an external voltage exceeds a discharge firing voltage. The sustain discharge is formed when a predetermined voltage is applied and predetermined discharge conditions are provided to the discharge cell. When the predetermined discharge conditions are not provided to the discharge cell, no discharge current flows, but the displacement currents flow to the discharge cell. The amount of the displacement currents is varied according to capacitance of a panel capacitor Cp, whose capacitance varies according to respective pixel types and elements. This type of driver has high power consumption. Because the panel capacitor consumes considerable reactive power, an energy regenerating circuit in a driving circuit is needed to reduce the consumption of the reactive power.
Known power recovery circuits include a circuit for using a power source of a ½ Vs voltage, where Vs denotes the amplitude of the sustain pulse. These circuits apply a sustain pulse having a voltage variation range between +½ Vs and −½ Vs. By using such a circuit, switches enduring a voltage of ½ Vs may be used.
In such known circuits, however, the number of switching operations for forming one sustain pulse may be greatly increased and a hard switching method may be adopted. When an energy regenerating circuit for a soft switching operation is provided, the number of the switching operations may be further increased, and the switching sequence becomes further complicated.
Accordingly, in the PDP drivers disclosed in the prior art, it is not easy to change the output voltage range, and manufacturing cost is increased because elements capable of enduring a high voltage need to be used.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.